This invention relates to a multiple-disk clutch particularly for use in a motor vehicle having a high-output engine mounted thereon.
A multiple-disk clutch is conventionally known as shown for example in Japanese Published Unexamined Utility Model Application No. 92827/1988. The multiple-disk clutch has a pressure plate disposed on an axially rear side opposing a clutch disk pressing surface which is formed on a flywheel. The pressure plate is attached to an input-side rotatable member constituted by the flywheel, a spacer and a clutch cover. A plurality of clutch disks are disposed between the pressing surface and the pressure plate with an intermediate plate being interposed between the clutch disks. A stopper surface is formed in the spacer. An axially rearward return position of the intermediate plate at the time of clutch disengagement is restricted by the abutting of an abutting plate against the stopper surface, the abutting plate being provided on an external periphery of the intermediate plate.
The abutting plate is dimensioned to be shorter than the distance between the stopper surface and the side surface of the flywheel opposing to the stopper surface by an amount equal to the disengaging allowance of the intermediate plate. The abutting plate is fastened, by a bolt via a coned disc spring, to the intermediate plate with the bolt being inserted into an axially elongated slot formed in the abutting plate enabling the abutting plate to be movable in an axial direction against the friction by the coned disc spring. In this arrangement, the mounting position of the abutting plate is adjusted at the time of clutch engagement so that the clearance dimension obtained by subtracting the thickness of the clutch disk on the front side of the intermediate plate from the distance between the intermediate plate and the pressure surface, i.e., the disengaging allowance of the intermediate plate, is always maintained constant in accordance with the wear of the front-side clutch disk.
When the number of revolutions of an engine is largely varied by racing or the like during clutch disengagement, the intermediate plate may sometimes be rotated accompanied by axial vibrations. At such time, the abutting plate of the above-described conventional disk clutch will strongly abut the stopper surface, and the abutting plate is caused to move forwards against the friction by the coned disc spring. Consequently, the return position of the intermediate plate is deviated backwards, and the intermediate plate will come into contact with the clutch disk on the side of the pressure plate, thereby giving rise to poor disengagement of the clutch.